Plant voltage-dependent anion channels are involved in host defense against Pseudomonas cichorii and in Bax-induced cell death.
The voltage-dependent anion channel (VDAC) is a major outer mitochondrial membrane protein. It is well documented that VDAC plays an important role in apoptosis, a kind of programmed cell death, in mammalian systems. However, little is known about the role of the plant counterpart during the process of plant-specific cell death such as pathogen-induced hypersensitive response. To address this issue, we isolated three VDAC full-length cDNAs (NtVDAC1-3) from Nicotiana tabacum. The deduced products, NtVDACs, share 78-85% identity and retain the conserved eukaryotic mitochondrial porin signature distal to their C-terminal regions. Mitochondrial localization of three NtVDACs in plant cells was confirmed via a green fluorescent protein fusion method. Then, we addressed the main issue concerning pathogenesis relation. The N. benthamiana orthologues of NtVDACs were upregulated by challenge with the non-host pathogen Pseudomonas cichorii, but not after challenge with the virulent pathogen P. syringae pv. tabaci. Both the pharmaceutical inhibition of VDAC and silencing of NbVDACs genes compromised the non-host resistance against P. cichorii, suggesting the involvement of VDACs in defense against non-host pathogen. Involvement of NbVDACs in Bax-mediated cell death was also verified using a similar approach.
Tateda
Chika
C
Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba, Sendai, Miyagi, 980-8577, Japan.
Yamashita
Koji
K
Takahashi
Fumio
F
Kusano
Tomonobu
T
Takahashi
Yoshihiro
Y
D000595:Amino Acid Sequence; D016923:Cell Death / Q000502:physiology*; D018076:DNA, Complementary / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D020868:Gene Silencing; D006861:Hydrogen Peroxide / Q000032:analysis; D008928:Mitochondria / Q000378:metabolism; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D011549:Pseudomonas / Q000472:pathogenicity*; D018749:RNA, Plant / Q000235:genetics; D016415:Sequence Alignment; D014026:Nicotiana / Q000235:genetics* / Q000378:metabolism / Q000382:microbiology; D050994:Voltage-Dependent Anion Channels / Q000235:genetics / Q000378:metabolism*; D051028:bcl-2-Associated X Protein / Q000378:metabolism*
D018076:DNA, Complementary; D010940:Plant Proteins; D018749:RNA, Plant; D050994:Voltage-Dependent Anion Channels; D051028:bcl-2-Associated X Protein; D006861:Hydrogen Peroxide